Abstract: An apparatus for producing an ignition spark in an internal combustion engine. The apparatus comprises an inductive ignition device having a primary coil and a secondary coil, flow of current through the primary coil being controlled by an electronic switching element (e.g., a transistor) responsive to a triggering signal. A rotatable body (e.g., the engine flywheel) having detectable features on a periphery thereof is also provided. A sensor device is located adjacent to the rotatable body at a fixed position and is operative to produce an output in response to the detectable features. The apparatus also includes a controller operative to receive an output from the sensor device and responsively produce the triggering signal so as to have a selected dwell time and ignition position.

Abstract: To accurately detect occurrence of erroneous detection of a crank pulse associated with dropout of a crank pulse or occurrence of noise. A cogless section is provided in cogs provided on an outer periphery of a crankshaft for transmitting a crank pulse. Occurrence of erroneous detection of a crank pulse is detected through use of an instantaneous rotational speed of the crankshaft computed from a crank pulse assigned to the cogless section and crank pulses assigned to cogs before and after the cogless section. When too few crank pulses are detected, a rapid increases arises in the instantaneous rotational speed of the crankshaft computed from the crank pulses after occurrence of a rapid decrease. The number of detected cramp pulses—which are fewer than the original crank pulses—is detected from the number of crank pulses existing between occurrence of a rapid decrease and occurrence of a rapid increase.

Abstract: In the embodiments described in the specification, a device having gear teeth to provide magnetic asymmetries rotates adjacent to a permanent magnet which is part of a mechanical mounting for a piezoelectric transducer. Relative motion between the gear teeth and the magnet subjects the transducer to a varying mechanical stress so that it generates a pulsed output voltage signal having an amplitude which is independent of surrounding influences.

Abstract: A displacement sensor is provided with first and second piezoelectric elements, a pair of electrodes at one and the other ends of each of the first and the second piezoelectric elements; a permanent magnet mechanically fixed to one end of the first piezoelectric element; a small piece mechanically fixed to one end of the second piezoelectric element and having almost the same weight as that of the permanent magnet; and a base plate to which the other ends of the first and the second piezoelectric elements are mechanically fixed; wherein the electrodes provided at the other end of each of the first and the second piezoelectric elements are electrically connected, and the electrodes provided at one end of each of the first and the second piezoelectric elements are used as output terminals.Also, a pair of small pieces made of a magnetic material and a non-magnetic material can be used instead of the above permanent magnet and small piece.

Abstract: A distributor for an ignition system that includes a plurality of optical switches (20) and a rotating member (40) having two windows (41, 42) spaced 180 degrees apart so that each switch is activated twice for each revolution of the distributor shaft. The distributor requires only as many optically coupled switches (20) as there are cylinders.

Abstract: An ignition distributor is disclosed which comprises an input terminal, output terminals, a rotor adapted to rotate with rotation of an engine and provided at its one end with a magnet, a first electrode facing the rotor and coupled to the input terminal, a piezo-conductive plate placed on the surface of the first electrode opposite to the rotor, second electrodes formed of magnetic material and connected to the output terminals, respectively, and the second electrodes circumferentially arranged on the piezo-conductive plate. When the rotor rotates to bring the magnet below one of the second electrodes, the one second electrode is attracted to exert a pressure on the piezo-conductive plate so as to render it conductive thereby establishing an electrical connection between the input terminal and the output terminal connected to the one second electrode.